In an OFDM (Orthogonal Frequency-Division Multiplexing) system, such as a Digital Terrestrial Television (DTT) system, a mismatch between the sampling frequencies used at the transmitter and the receiver can result in serious degradation of performance. The offset in sampling frequency, or sampling frequency offset (SFO), causes a loss of orthogonality between carriers and hence inter-carrier-interference (ICI).
Methods have been developed to calculate SFO which use reference symbols. In these methods, a received symbol is correlated against a reference symbol and from this the SFO may calculated in a number of different ways. There exists a need in the art for improvement to methods for calculating SFO.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known methods of calculating SFO.